Technical Field
Embodiments of the present disclosure relate to a field of optical identification, and more particularly, to an optical fingerprint detection apparatus and a display device.
Description of the Related Art
With the development of fingerprint identification technology, it has been widely used in many fields, such as electronic equipment terminals including a mobile phone, a tablet computer, a television and the like, or security protection systems including an access control device, a steel safe and the like. Fingerprint acquisition is implemented mainly through an optical imaging technology, a capacitive imaging technology, an ultrasonic imaging technology or the like. Optical fingerprint identification technology can achieve a relatively large identification range, and has a relatively low cost.
At present, for example, in a LCD display, fingerprint identification is generally carried out in such a manner that fingerprint imaging is achieved through diffuse reflection by using a backlight plate and an optical imaging device. For example, upon illuminating a finger using a backlight as a light source, light ray is diffusely reflected back to an imaging sensor for imaging. A fingerprint identification image is formed by means of a difference between intensities of divergent light diffusely reflected from a trough (hereinafter referred to as a valley) and a crest (hereinafter referred to as a ridge) of a finger fingerprint. Since the energy of the diffusely reflected light is relatively weak and a signal difference between the valley and the ridge of the fingerprint is relatively small, such a manner raises a significantly high requirement for light transmittance of a portion where the diffusely reflected light transmits through and the sensitivity of a sensor, and presents a low anti-interference capability to other light rays.